JP2018179576A - Physical quantity detector and method for acquiring temperature correction signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a temperature drift of the whole of a physical quantity detector simply at low cost.SOLUTION: A detection signal switching unit 73, switched in correspondence to a switching state of an excitation signal switching unit 71, is constituted so as to output a first detection signal D to a first signal holding unit 74a when a first excitation signal A is applied to an excitation coil 20, and constituted so as to output a second detection signal E to a second signal holding unit 74b when a second excitation signal B is applied to the excitation coil 20. When a difference is taken with the same angle of rotation of a revolving shaft 60 at the same temperature of a brushless resolver 13 by subtracting a difference between the first detection signal D and the second detection signal E by a subtraction unit 75, a result is that a difference in temperature characteristics of the brushless resolver 13 due to the frequency of an excitation signal derives, making it possible to obtain a temperature correction signal F as temperature correction information usable for correction of the temperature characteristics.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a physical quantity detector and a temperature correction signal acquisition method thereof, and more particularly to a novel improvement in detecting a physical quantity by electromagnetic induction.

  For example, in a physical quantity detector such as a resolver or differential transformer (LVDT) that uses an electromagnetic induction type physical quantity detector that is provided with a coil and detects a physical quantity by electromagnetic induction, the physical quantity resulting from the temperature characteristics of the coil Means are provided for correcting temperature drift of the detector. As a structure of the physical quantity detector which detects a physical quantity by the conventional electromagnetic induction, the content described in the following patent document 1 can be mentioned as FIG. 4, for example. That is, in the resolver 10 constituting a physical quantity detector that detects a physical quantity by electromagnetic induction, a current detection circuit 30 detects a current flowing through the exciting coil 20 of the resolver 10 in order to reduce temperature drift of the resolver 10; By correcting the excitation signal A applied to the excitation coil 20 by the phase correction circuit 31 based on the detection output of the current detection circuit 30, the temperature drift of the resolver 10 is reduced.

  Moreover, as another example of the structure of the physical quantity detector which detects a physical quantity by the conventional electromagnetic induction, the content described, for example in following patent document 2 can be mentioned as FIG. In a resolver that constitutes a physical quantity detector that detects a physical quantity by electromagnetic induction, a pair of temperature detection terminal pins 41 is connected to the terminal holding portion 40 of the resolver stator structure 11 of the resolver. Thermistor 42 is connected between them, and the temperature detected by the thermistor 42 is configured to correct the temperature drift of the resolver stator structure 11.

Unexamined-Japanese-Patent No. 11-325813 gazette Unexamined-Japanese-Patent No. 2010-32291

  In the conventional resolver 10 described in Patent Document 1 described above, the temperature characteristic of the excitation signal A is corrected, but the temperature characteristic of the resolver 10 as a whole is not considered because the temperature characteristic of the output coil is not taken into consideration. There is a problem that it does not correct drift.

  Further, in the conventional resolver stator structure 11 described in the above-mentioned Patent Document 2, it is necessary to provide the thermistor 42, and the number of parts and the number of manufacturing steps of the resolver stator structure 11 are increased. The problem is that the cost of

  The present invention has been made to solve such a problem, and in particular, a physical quantity detector capable of correcting temperature drift of the entire physical quantity detector simply and inexpensively, and detection signal correction information in the physical quantity detector The purpose is to provide an acquisition method.

  According to the physical quantity detector of the present invention, an excitation coil to which an excitation signal is applied, and an excitation signal switching unit for switching an excitation signal applied to the excitation coil to a first excitation signal or a second excitation signal; A detection coil to which a detection signal is output according to the physical quantity to be detected and each excitation signal, a signal processing unit connected to the detection coil, processing the detection signal, and outputting a processed detection signal; According to the switching state of the first signal holding unit and the second signal holding unit, in which the detection signal after processing is held, and the excitation signal switching unit, the output destination of the after processing detection signal is the first signal holding unit or A physical quantity detector comprising a detection signal switching unit for switching to the second signal holding unit, wherein the first excitation signal and the second excitation signal have different frequencies, and the first excitation signal is the excitation coil. Applied to If it is, the post-processing detection signal is switched by the detection signal switching unit to be output as the first detection signal to the first signal holding unit, and the second excitation signal is applied to the excitation coil. In this case, the post-processing detection signal is switched by the detection signal switching unit to be output to the second signal holding unit as a second detection signal, and is held by the first signal holding unit and the second signal holding unit. The excitation signal switching unit is configured to obtain the difference between the detection signals being obtained as a temperature correction signal with respect to the detection result of the physical quantity to be detected, and with the physical quantity to be detected being constant. The excitation signal applied to the coil is switched between the first excitation signal and the second excitation signal, and the physical quantity is a rotation angle, and the rotation angle is detected. A rotating physical quantity detector, also, the physical quantity is a linear position, a configuration is a differential transformer for detecting the linear position.

  Further, according to the method of acquiring a temperature correction signal of a physical quantity detector according to the present invention, an excitation coil to which an excitation signal is applied, and an excitation signal applied to the excitation coil are switched to a first excitation signal or a second excitation signal. An excitation signal switching unit, a detection coil to which a detection signal is output according to the physical quantity to be detected and each excitation signal, and the detection coil are connected to process the detection signal and output a processed detection signal According to the switching state of the signal processing unit, the first signal holding unit and the second signal holding unit, and the excitation signal switching unit in which the post-processing detection signal is input and held, the output of the post-processing detection signal In the physical quantity detector including a detection signal switching unit for switching the first to the first signal holding unit or the second signal holding unit, the first excitation signal and the second excitation signal have different frequencies, and the first excitation signal and the second excitation signal have different frequencies. 1 When a signal is applied to the excitation coil, the post-processing detection signal is switched by the detection signal switching unit to be output as the first detection signal to the first signal holding unit, and the second excitation signal is output. Is applied to the excitation coil, the post-processing detection signal is switched by the detection signal switching unit to be output to the second signal holding unit as a second detection signal, and the first signal holding unit And a configuration in which a difference between the detection signals held in the second signal holding unit is obtained as a temperature correction signal for the detection result of the physical quantity to be detected, and the physical quantity to be detected is constant. The excitation signal switching unit is configured to switch the excitation signal applied to the excitation coil to the first excitation signal and the second excitation signal.

  According to the electromagnetic induction type detection unit of the present invention, when the first excitation signal and the second excitation signal have different frequencies and the first excitation signal is applied to the excitation coil, the post-processing detection is performed The signal is switched by the detection signal switching unit to be output to the first signal holding unit as a first detection signal, and when the second excitation signal is applied to the excitation coil, the post-processing detection signal Is switched by the detection signal switching unit to be output to the second signal holding unit as a second detection signal, and the detection signals of the respective detection signals held by the first signal holding unit and the second signal holding unit. Since the difference is obtained as a temperature correction signal for the detection result of the physical quantity to be detected, the temperature drift of the physical quantity detector can be corrected easily and inexpensively.

It is sectional drawing of a motor provided with the resolver which comprises the physical quantity detector which concerns on embodiment of this invention. It is a half section view of the resolver shown in FIG. It is the schematic of control structure of a resolver and a resolver control part shown in FIG. It is a circuit structure schematic of the conventional resolver. It is the schematic of the resolver stator structure of the conventional resolver.

Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 3 of the attached drawings. The same or equivalent parts as in the conventional example will be described with the same reference numerals.
FIG. 1 is a cross-sectional view of a motor provided with a physical quantity detector according to an embodiment of the present invention. The physical quantity detector is, for example, a brushless resolver 13 mounted inside a cover 51 of a known motor 50 such as an AC servomotor, and constitutes a physical quantity detector that detects a physical quantity by electromagnetic induction. A ring-shaped stator 15 is provided on the inner wall 14 a of the case 14 of the brushless resolver 13. A rotor 21 is provided inside the annular stator 15.

  The rotor 21 is provided with a rotating shaft 60 which penetrates the case 14 and rotates with the rotor 21. A motor rotation shaft 52 of the motor 50 is connected to the rotation shaft 60, and the rotation shaft 60 and the motor rotation shaft 52 rotate together. Thus, the rotation angle of the motor rotation shaft 52 is input to the brushless resolver 13 via the rotation shaft 60. That is, the physical quantity to be detected (the rotation angle of the motor rotation shaft 52 of the motor 50 in this embodiment) is input to the brushless resolver 13 via the rotation shaft 60.

  FIG. 2 shows a half sectional view of the brushless resolver 13 shown in FIG. A detection coil 15a is wound around the annular stator 15 as a stator coil. An exciting coil 20 is wound around the rotor 21 as a rotor coil. Further, first and second rotary transformers 16 and 17 for exciting the exciting coil 20 are provided in the case 14. The second rotary transformer 17 on the secondary side is connected to the exciting coil 20. A lead wire for excitation signal input to the first rotary transformer 16 on the primary side and a lead wire for detection signal output from the detection coil 15a are bundled as a lead wire 18 and the outside of the case 14 It has been pulled out. The lead wire 18 is connected to a resolver control unit 70 that controls the brushless resolver 13.

  FIG. 3 is a schematic view of a control configuration of the brushless resolver 13 and the resolver control unit 70 in the embodiment of the present invention. In FIG. 3, the description of the first and second rotary transformers 16 and 17 is omitted. An excitation signal switching unit 71 is connected to the excitation coil 20 via the first and second rotary transformers 16 and 17 (see FIG. 2) and the lead wire 18.

  The excitation signal switching unit 71 receives the first excitation signal A and the second excitation signal B, and switches whether to output the first excitation signal A or the second excitation signal B by the switching signal X. Are configured to be As the excitation signal switching unit 71, any signal switching unit such as a switching element may be used, for example.

  The excitation coil 20 is magnetically coupled to the detection coil 15 a to constitute an electromagnetic induction detection unit 19. The output of the detection coil 15 a is a detection signal C, and is connected to the signal processing unit 72 of the resolver control unit 70 via the lead wire 18.

  The output of the signal processing unit 72 is connected to, for example, a control unit (not shown) of the motor 50 (see FIG. 1). Further, a detection signal switching unit 73 is connected to the output of the signal processing unit 72. The detection signal switching unit 73 is connected to the first signal holding unit 74a and the second signal holding unit 74b, and the switching signal X causes the first signal holding unit 74a and the second signal holding unit 74b to be switched. It is configured to be able to switch to which one of the post-processing detection signals C 'is output. As the detection signal switching unit 73, for example, any signal switching unit such as a switching element may be used.

  The first signal holding unit 74a and the second signal holding unit 74b are configured to be able to hold the inputted post-processing detection signal C '. The outputs of the first and second signal holding units 74a and 74b are connected to a subtraction unit 75, and the output of the subtraction unit 75 is, for example, a temperature correction signal F to a control unit (not shown) of the motor 50 (see FIG. 1). Connected as.

Next, the operation of the brushless resolver 13 of this embodiment will be described with reference to FIGS. 1 and 3.
As shown in FIG. 1, the rotation shaft 60 of the brushless resolver 13 rotates at the same rotation angle as the motor rotation shaft 52. At this time, as shown in FIG. 3, the excitation signal is applied to the excitation coil 20 and excited to thereby rotate the rotation shaft 60 from the detection coil 15 a magnetically joined to the excitation coil 20. The detection signal C corresponding to the angle and the frequency of the excitation signal is output to the signal processing unit 72. The signal processing unit 72 performs signal processing on the input signal, and outputs the processed signal to a control unit (not shown) of the motor 50 (see FIG. 1) as the post-processing detection signal C ′. As a result, the rotation angle of the motor rotation shaft 52 is detected as the post-processing detection signal C ′.

  At this time, in a state in which the rotation angle of the motor rotation shaft 52 (see FIG. 1) is kept constant, that is, in a state in which the rotation angle of the rotation shaft 60 is kept constant An excitation signal A and a second excitation signal B having a predetermined excitation frequency f 2 are input to the excitation signal switching unit 71. Also, during the following operation, the temperature of the brushless resolver 13 does not change. Next, the excitation signal switching unit 71 is switched by the switching signal X so that the first excitation signal A is input to the excitation signal switching unit 71. Then, the first excitation signal A input to the excitation signal switching unit 71 is applied to the excitation coil 20.

  Next, when the first excitation signal A is applied to the excitation coil 20, the detection signal C corresponding to the rotation angle of the rotary shaft 60 and the frequency f1 of the first excitation signal A is the detection coil 15a. To the signal processing unit 72. The detection signal C is subjected to signal processing in the signal processing unit 72, and the post-processing detection signal C ′ is input to the detection signal switching unit 73.

  The detection signal switching unit 73 is switched by the switching signal X to output the post-processing detection signal C ′ which has been subjected to the signal processing to the first signal holding unit 74 a. At this time, the post-processing detection signal C ′ output to the first signal holding unit 74 a is referred to as a first detection signal D.

  That is, the detection signal switching unit 73 switches according to the switching state of the excitation signal switching unit 71, and when the first excitation signal A is applied to the excitation coil 20, the first signal holding unit 74a. And the first detection signal D is output. The first detection signal D is held in the first signal holding unit 74a.

  Next, the excitation signal switching unit 71 is switched by the switching signal X so that the excitation signal switching unit 71 outputs the second excitation signal B. Then, the second excitation signal B input to the excitation signal switching unit 71 is applied to the excitation coil 20.

  Next, when the second excitation signal B is applied to the excitation coil 20, a signal corresponding to the rotation angle of the rotary shaft 60 and the frequency f2 of the excitation signal is output to the signal processing unit 72. The detection signal C is subjected to signal processing in the signal processing unit 72, and the post-processing detection signal C ′ is input to the detection signal switching unit 73.

  The detection signal switching unit 73 is switched by the switching signal X to output the post-processing detection signal C 'to the second signal holding unit 74b. At this time, the post-processing detection signal C ′ output to the second signal holding unit 74 b is referred to as a second detection signal E.

  That is, the detection signal switching unit 73 is configured to output the second detection signal E to the second signal holding unit 74b when the second excitation signal B is applied to the excitation coil 20. . The second detection signal E is held in the second signal holding unit 74b.

  The first detection signal D held by the first signal holding unit 74a and the second detection signal E held by the second signal holding unit 74b are subtracted by the subtraction unit 75, and the temperature is reduced. It is output as the correction signal F. That is, the temperature correction signal F applies the first excitation signal A of the frequency f 1 to the excitation coil 20 in a state where the rotation shaft 60 has a constant rotation angle and the temperature of the brushless resolver 13 is constant. It is a difference between the first detection signal D in this case and the second detection signal E when the second excitation signal B of frequency f2 is applied to the exciting coil 20.

  The resistance of the excitation coil 20 and the detection coil 15a due to the change of the rotation angle of the rotary shaft 60 to be detected is the change in the magnetic flux generated in the excitation coil 20 by the excitation signal or the electromotive force generated in the detection coil 15a by electromagnetic induction. Changes in impedance such as components and reactance components are closely related. On the other hand, the impedance generally has different temperature characteristics between the resistance component and the reactance component, and the balance between the resistance component and the reactance component changes with the change of the frequency of the excitation signal. Changes with the frequency of the excitation signal.

  Therefore, for the first excitation signal A of the frequency f1 and the second excitation signal B of the frequency f2, the first detection signal D at the same rotation angle of the rotation shaft 60 and the same temperature of the brushless resolver 13. When the difference between the second detection signal E and the second detection signal E is subtracted by the subtraction unit 75 and the difference is taken, the difference of the temperature characteristic of the brushless resolver 13 depending on the frequency of the excitation signal is taken out. The temperature correction signal F can be obtained as possible temperature correction information.

  Thus, the excitation coil 20 to which the first and second excitation signals A and B are applied, and the excitation signal applied to the excitation coil 20 are switched to the first excitation signal A or the second excitation signal B. And the detection coil 15a to which the detection signal C is output according to the physical quantity to be detected and the first and second excitation signals A and B, and the detection coil 15a. The signal processing unit 72 that processes the detection signal C and outputs the processed detection signal C ′, and the first signal holding unit 74 a and the second that hold the processed detection signal C ′. According to the switching state of the signal holding unit 74b and the excitation signal switching unit 71, the output destination of the post-processing detection signal C ′ is switched to the first signal holding unit 74a or the second signal holding unit 74b. Detection signal switching unit 73 And the first excitation signal A and the second excitation signal B are different in frequency, and the first excitation signal A is applied to the excitation coil 20 after the processing. The detection signal C ′ is switched by the detection signal switching unit 73 to be output to the first signal holding unit 74 a as the first detection signal D, and the second excitation signal B is applied to the excitation coil 20. If it is, the post-processing detection signal C ′ is switched by the detection signal switching unit 73 to be output to the second signal holding unit 74 b as the second detection signal E, and the first signal holding unit 74 a and Since the difference between the detection signals D and E held in the second signal holding unit 74b is obtained as the temperature correction signal F with respect to the detection result of the physical quantity to be detected, the block is simple and inexpensive. Shiresurezoruba 13 can correct the temperature drift of the whole.

  Also, since the excitation signal applied to the excitation coil 20 by the excitation signal switching unit 71 is switched between the first excitation signal A and the second excitation signal B while the physical quantity of the brushless resolver 13 is constant. Thus, the temperature drift of the entire brushless resolver 13 can be corrected more reliably.

  Also, the excitation coil 20 to which the first and second excitation signals A and B are applied, and the excitation signal applied to the excitation coil 20 are switched to the first excitation signal A or the second excitation signal B. And the detection coil 15a to which the detection signal C is output according to the physical quantity to be detected and the first and second excitation signals A and B, and the detection coil 15a. The signal processing unit 72 that processes the detection signal C and outputs the post-processing detection signal C ′, and the first signal holding unit 74 a and the above that receive and hold the post-processing detection signal C ′ The output destination of the post-processing detection signal C ′ is switched to the first signal holding unit 74 a or the second signal holding unit 74 b according to the switching state of the second signal holding unit 74 b and the excitation signal switching unit 71. Detection signal of In the physical quantity detector including the conversion unit 73, when the first excitation signal A and the second excitation signal B have different frequencies and the first excitation signal A is applied to the excitation coil 20, The post-processing detection signal C ′ is switched by the detection signal switching unit 73 to be output to the first signal holding unit 74 a as the first detection signal D, and the second excitation signal B is applied to the excitation coil 20. If it has, the post-processing detection signal C ′ is switched by the detection signal switching unit 73 to be output to the second signal holding unit 74 b as the second detection signal E, and the first signal holding unit 74a and the temperature of the physical quantity detector which obtains the difference between the detection signals D and E held by the second signal holding unit 74b as the temperature correction signal F with respect to the detection result of the physical quantity to be detected Since a positive signal acquisition method can be easily and inexpensively correcting the temperature drift of the entire physical quantity detector.

  In addition, the physical quantity in which the excitation signal applied to the excitation coil 20 by the excitation signal switching unit 71 is switched between the first excitation signal A and the second excitation signal B while the physical quantity of the brushless resolver 13 is constant. Since the method of acquiring the temperature correction signal of the detector, the temperature drift of the whole physical quantity detector can be corrected more reliably.

  Further, in this embodiment, the physical quantity detector that detects the physical quantity by electromagnetic induction is the brushless resolver 13 that is a rotation angle detector, but for example, the rotation angle detection that detects the physical quantity by any electromagnetic induction such as RVDT. It may be a container. Thus, even if the physical quantity to be detected is the rotation angle, temperature drift of the entire physical quantity detector can be corrected easily and inexpensively.

  Further, in this embodiment, the physical quantity detector for detecting a physical quantity by electromagnetic induction is the brushless resolver 13, but it is a physical quantity detector for detecting a linear position as a physical quantity by electromagnetic induction such as LVDT. It is also good. Thus, even if the physical quantity to be detected is at a linear position, temperature drift of the entire physical quantity detector can be corrected easily and inexpensively.

  Further, in this embodiment, the brushless resolver 13 as a physical quantity detector for detecting a physical quantity by electromagnetic induction is provided in the motor 50, but the present invention is not limited to this. The present invention can be used as a physical quantity detector or method for detecting any physical quantity.

  In this embodiment, the brushless resolver 13 has the detection coil 15a wound around the annular stator 15 as a stator coil, and the excitation coil 20 wound around the rotor 21 as a rotor coil. The resolver may be a resolver in which the excitation coil 20 is wound around the annular stator 15 and the detection coil 15a is wound around the rotor 21, or a resolver other than a brushless resolver.

  The summary of the physical quantity detector according to the present invention is as follows. That is, the excitation coil 20 to which the first and second excitation signals A and B are applied, and the excitation signal applied to the excitation coil 20 are switched to the first excitation signal A or the second excitation signal B. It is connected to the excitation signal switching unit 71, the detection coil 15a to which the detection signal C is output according to the physical quantity to be detected and the first and second excitation signals A and B, and the detection coil 15a, The signal processing unit 72 that processes the detection signal C and outputs the post-processing detection signal C ′, and the first signal holding unit 74 a and the second signal holding where the post-processing detection signal C ′ is held The detection signal for switching the output destination of the post-processing detection signal C 'to the first signal holding unit 74a or the second signal holding unit 74b according to the switching state of the unit 74b and the excitation signal switching unit 71 Switching unit 73 and The physical quantity detector, wherein the first excitation signal A and the second excitation signal B have different frequencies, and when the first excitation signal A is applied to the excitation coil 20, the post-processing detection The signal C ′ is switched by the detection signal switching unit 73 to be output as the first detection signal D to the first signal holding unit 74 a, and the second excitation signal B is applied to the excitation coil 20. In this case, the post-processing detection signal C ′ is switched by the detection signal switching unit 73 to be output to the second signal holding unit 74 b as the second detection signal E, and the first signal holding unit 74 a and the The difference between the detection signals D and E held in the second signal holding unit 74b is obtained as the temperature correction signal F for the detection result of the physical quantity to be detected, and the bra The excitation signal applied to the excitation coil 20 by the excitation signal switching unit 71 is switched between the first excitation signal A and the second excitation signal B while the physical quantity of the res resolver 13 is constant, and The physical quantity is a rotational angle, and the rotational physical quantity detector detects the rotational angle, and the physical quantity is a linear position, and the differential transformer detects the linear position. The excitation coil 20 to which the first and second excitation signals A and B are applied, and an excitation signal applied to the excitation coil 20 are switched to the first excitation signal A or the second excitation signal B. The excitation signal switching unit 71 is connected to the detection coil 15a to which the detection signal C is output according to the physical quantity to be detected and the first and second excitation signals A and B, and the detection coil 15a, The signal processing unit 72 that processes the detection signal C and outputs the post-processing detection signal C ′, and the first signal holding unit 74 a and the first signal holding unit 74a that receive and hold the post-processing detection signal C ′ The output destination of the post-processing detection signal C ′ is switched to the first signal holding unit 74 a or the second signal holding unit 74 b according to the switching state of the two signal holding unit 74 b and the excitation signal switching unit 71. In the physical quantity detector including the detection signal switching unit 73, the first excitation signal A and the second excitation signal B have different frequencies, and the first excitation signal A is applied to the excitation coil 20. Is switched so that the post-processing detection signal C ′ is output to the first signal holding unit 74a as the first detection signal D by the detection signal switching unit 73, and the second excitation signal B is output as the excitation coil. 20 When it is applied, the post-processing detection signal C ′ is switched by the detection signal switching unit 73 to be output to the second signal holding unit 74 b as the second detection signal E, and the first signal holding is performed. Temperature correction signal acquiring method of a physical quantity detector which obtains the difference between the detection signals D and E held in the section 74a and the second signal holding section 74b as the temperature correction signal F with respect to the detection result of the physical quantity to be detected In the state where the physical quantity of the brushless resolver 13 is constant, the excitation signal applied to the excitation coil 20 by the excitation signal switching unit 71 is the first excitation signal A and the second excitation signal B. It is a temperature correction signal acquisition method of the physical quantity detector switched.

  A physical quantity detector according to the present invention includes an excitation coil to which an excitation signal is applied, an excitation signal switching unit for switching an excitation signal applied to the excitation coil to a first excitation signal or a second excitation signal, and a detection target A detection coil to which a detection signal is output according to the physical quantity and each excitation signal, and a signal processing unit connected to the detection coil for processing the detection signal and outputting a processed detection signal, and the post-processing detection The output destination of the post-processing detection signal corresponds to the first signal holding unit or the second signal holding unit according to the first signal holding unit, the second signal holding unit, and the switching state of the excitation signal switching unit. A physical quantity detector comprising a detection signal switching unit for switching to a signal holding unit, wherein the first excitation signal and the second excitation signal have different frequencies, and the first excitation signal is applied to the excitation coil. Where you are Is switched so that the post-processing detection signal is outputted to the first signal holding unit as the first detection signal by the detection signal switching unit, and the second excitation signal is applied to the excitation coil. The post-processing detection signal is switched by the detection signal switching unit to be output to the second signal holding unit as a second detection signal, and is held by the first signal holding unit and the second signal holding unit. The difference between the detection signals is obtained as a temperature correction signal for the detection result of the physical quantity to be detected, so that the temperature drift of the entire physical quantity detector can be corrected easily and inexpensively.

13 Brushless resolver 15a detection coil 20 excitation coil 71 excitation signal switching unit 73 detection signal switching unit 74a first signal holding unit 74b second signal holding unit A first excitation signal B second excitation signal C detection signal C 'detection signal after processing D First detection signal E Second detection signal F Temperature correction signal

Claims (6)

An excitation coil (20) to which an excitation signal is applied;
An excitation signal switching unit (71) for switching an excitation signal applied to the excitation coil (20) to a first excitation signal (A) or a second excitation signal (B);
A detection coil (15a) for outputting a detection signal (C) according to the physical quantity to be detected and each of the excitation signals (A, B);
A signal processing unit (72) connected to the detection coil (15a), which processes the detection signal (C) and outputs a processed detection signal (C ');
A first signal holding unit (74a) and a second signal holding unit (74b) in which the post-processing detection signal (C ′) is held;
According to the switching state of the excitation signal switching unit (71), the output destination of the post-processing detection signal (C ′) is switched to the first signal holding unit (74a) or the second signal holding unit (74b) A physical quantity detector comprising the detection signal switching unit (73) of
The first excitation signal (A) and the second excitation signal (B) have different frequencies,
When the first excitation signal (A) is applied to the excitation coil (20), the post-processing detection signal (C ') is processed as a first detection signal (D) by the detection signal switching unit (73). The signal is switched to be output to the first signal holding unit (74a), and when the second excitation signal (B) is applied to the exciting coil (20), the post-processing detection signal (C ') Is switched by the detection signal switching unit (73) to be output to the second signal holding unit (74b) as a second detection signal (E), and the first signal holding unit (74a) and the second signal A physical quantity detection characterized in that a difference between the detection signals (D, E) held in the holding section (74b) is obtained as a temperature correction signal (F) for the detection result of the physical quantity to be detected. vessel.   The excitation signal applied to the excitation coil (20) by the excitation signal switching unit (71) with the physical quantity of the detection target being constant is the first excitation signal (A) and the second excitation signal (B The physical quantity detector according to claim 1, characterized in that   The physical quantity detector according to claim 1 or 2, wherein the physical quantity is a rotational angle, and the physical quantity detector is a rotational physical quantity detector that detects the rotational angle.   The physical quantity detector according to claim 1, wherein the physical quantity is a linear position, and the physical quantity is a differential transformer that detects the linear position. An excitation coil (20) to which an excitation signal is applied;
An excitation signal switching unit (71) for switching an excitation signal applied to the excitation coil (20) to a first excitation signal (A) or a second excitation signal (B);
A detection coil (15a) for outputting a detection signal (C) according to the physical quantity to be detected and each of the excitation signals (A, B);
A signal processing unit (72) connected to the detection coil (15a), which processes the detection signal (C) and outputs a processed detection signal (C ');
A first signal holding unit (74a) and a second signal holding unit (74b), which receive and hold the post-processing detection signal (C ′);
According to the switching state of the excitation signal switching unit (71), the output destination of the post-processing detection signal (C ′) is switched to the first signal holding unit (74a) or the second signal holding unit (74b) In the physical quantity detector including the detection signal switching unit (73) of
The first excitation signal (A) and the second excitation signal (B) have different frequencies,
When the first excitation signal (A) is applied to the excitation coil (20), the post-processing detection signal (C ') is processed as a first detection signal (D) by the detection signal switching unit (73). The signal is switched to be output to the first signal holding unit (74a), and when the second excitation signal (B) is applied to the exciting coil (20), the post-processing detection signal (C ') Is switched by the detection signal switching unit (73) to be output to the second signal holding unit (74b) as a second detection signal (E), and the first signal holding unit (74a) and the second signal Temperature correction of the physical quantity detector characterized in that the difference between the detection signals (D, E) held in the holding unit (74b) is obtained as the temperature correction signal (F) for the detection result of the physical quantity to be detected Signal acquisition method. The excitation signal applied to the excitation coil (20) by the excitation signal switching unit (71) with the physical quantity of the detection target being constant is the first excitation signal (A) and the second excitation signal (B The method of acquiring a temperature correction signal of a physical quantity detector according to claim 5, characterized in that

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